Using WordPress ‘get_{$adjacent}_post_excluded_terms’ PHP filter

The get_{$adjacent}_post_excluded_terms WordPress PHP filter is used to modify the IDs of terms excluded from adjacent post queries.

Usage

add_filter('get_next_post_excluded_terms', 'my_custom_excluded_terms');
add_filter('get_previous_post_excluded_terms', 'my_custom_excluded_terms');

function my_custom_excluded_terms($excluded_terms) {
    // Your custom code here
    return $excluded_terms;
}

Parameters

• $excluded_terms: int[]|string – An array of excluded term IDs or an empty string if none were provided.

More information

See WordPress Developer Resources:

• get_next_post_excluded_terms
• get_previous_post_excluded_terms

Examples

Exclude specific categories

Exclude posts from categories with IDs 3 and 5.

add_filter('get_next_post_excluded_terms', 'exclude_specific_categories');
add_filter('get_previous_post_excluded_terms', 'exclude_specific_categories');

function exclude_specific_categories($excluded_terms) {
    $excluded_terms = array(3, 5);
    return $excluded_terms;
}

Exclude current post’s category

Exclude posts from the current post’s category.

add_filter('get_next_post_excluded_terms', 'exclude_current_category');
add_filter('get_previous_post_excluded_terms', 'exclude_current_category');

function exclude_current_category($excluded_terms) {
    $current_category = wp_get_post_categories(get_the_ID());
    return $current_category;
}

Exclude multiple categories

Exclude posts from multiple categories by providing an array of category IDs.

add_filter('get_next_post_excluded_terms', 'exclude_multiple_categories');
add_filter('get_previous_post_excluded_terms', 'exclude_multiple_categories');

function exclude_multiple_categories($excluded_terms) {
    $excluded_terms = array(1, 2, 3, 4);
    return $excluded_terms;
}

Exclude categories with a custom function

Exclude categories based on a custom function.

add_filter('get_next_post_excluded_terms', 'exclude_custom_function_categories');
add_filter('get_previous_post_excluded_terms', 'exclude_custom_function_categories');

function exclude_custom_function_categories($excluded_terms) {
    $categories = get_categories();
    $exclude = array();

    foreach ($categories as $category) {
        if (custom_function($category)) {
            $exclude[] = $category->term_id;
        }
    }

    return $exclude;
}

Reset excluded terms

Reset the excluded terms, allowing posts from all categories.

add_filter('get_next_post_excluded_terms', 'reset_excluded_terms');
add_filter('get_previous_post_excluded_terms', 'reset_excluded_terms');

function reset_excluded_terms($excluded_terms) {
    $excluded_terms = array();
    return $excluded_terms;
}